Mayor Michael Bloomberg proposed legislation Monday that would prohibit citywide retailers from showing tobacco products, a proposal that would make New York the first city in the nation to ban cigarette displays.

Under legislation set to be introduced in the City Council this week, sellers would be required to keep tobacco products out of sight except during a purchase by an adult or during restocking. Tobacco products would be required to be kept in cabinets, drawers, under the counter, behind a curtain or in any concealed location.

“This legislation will help prevent another generation from the ill health and shorter life expectancy that comes with smoking,” Mr. Bloomberg said on Monday.

City Council Speaker Christine Quinn said she is “very, very open” to the mayor’s proposed ban on tobacco displays. “It’s something that the mayor’s requested we have hearings on, which we will do,” she told reporters.

If passed by lawmakers, this first-of-its kind policy in the U.S. would mark latest in a series of aggressive and sometimes unpopular public-health initiatives backed by Mr. Bloomberg

On the antitobacco front, Mr. Bloomberg succeeded in 2002 in passing a ban on smoking in restaurants and bars with cooperation of the council, a policy that provoked a backlash from some his first term but has since been embraced by the city. More recently, the mayor convinced the council to extend that ban to parks and beaches, public plazas and marinas.

Just last week, a state judge blocked the mayor’s plan to prohibit restaurants, mobile food carts, delis and concessions at movie theaters, stadiums or arenas from selling sugary drinks in cups or containers larger than 16 ounces. The ban was set to begin on March 12.

In his ruling, Supreme Court Judge Milton Tingling found that Mr. Bloomberg had exceeded his authority by placing the beverage issue before the city’s Board of Health, which he appoints, instead of going through the City Council. The mayor and the city’s top lawyer declared their intention to appeal the ruling.

The mayor moved to ban the use of artificial trans-fats in foods and required the posting of calorie counts at chain restaurants in 2006, also with the help of the Board of Health. The Council later voted to approve the trans-fat ban.